BiologyBiology ofof ReproductionReproduction SpringSpring 20072007 . Louis Guillette . Office: 528 Bartram Hall . Office Hours: . Tuesday/Thursday period 4 (10:40-11:25) . Phone: 392-1098; . Email: [email protected] . http://www.zoo.ufl.edu/ljg/Courses/index.htm GGuuiilllleettette llaabboorraatotorryy

• 22nd year at UF • Research focus on reproductive biology • Teaching: general biology - graduate studies The World of Reproductive Biology

Molecular Biosphere Field-based Field-based seconds eons Studies Studies Cellular Ecosystem Studies minutes centuries Studies

Tissue Community

hours decades Laboratory-based Laboratory-based Organ Organism Population years Lab or Field-based Studies

Thanks to John Moran and Rex Hess for use of photos presented here. Guillette - UF EEvvooluluttiioonn:: DDaarrwwiinn’’ss mmaaiinn iiddeeaass 1) Natural selection is "differential success in reproduction"

a) Unequal ability of individuals to survive and reproduce ReproductionReproduction • central to biology and evolution – "differential reproduction" • involves production, growth and differentiation of new individuals • interdisciplinary in scope EEvvooluluttiioonn:: DDaarrwwiinn’’ss mmaaiinn iiddeeaass

2) interaction between the environment and the variability inherent among individuals making up a population EEvvooluluttiioonn:: DDaarrwwiinn’’ss mmaaiinn iiddeeaass

3) adaptation of populations of organisms to their environment insecticideinsecticide resistanceresistance inin insectsinsects

Insects with chromosome for resistance differentially reproduce

Figure 22.12 Evolution of insecticide resistance in insect populations ModelModel SystemsSystems • 90% of the recent research in mammals is focused on 10 species • 0.02% of present day vertebrate species! • these 'models' have "pointed the way" but do not clearly represent the diversity present TTeerrmmss YYoouu SShhoouuldld KKnnooww •• PPLLEESSIIOOMMOORRPPHHIICC -- pprriimmiittiivvee •• AAPPOOMMOORRPPHHIICC –– ddeerriivveedd

•• HHOOMMOOLLOOGGYY-- cchhaarraacctteerrss sshhaarree ssiimmiillaarr ddeessiiggnn aanndd ccoommmmoonn eevvoolluuttiioonnaarryy oorriiggiinn •• AANNAALLOOGGYY -- iinnddeeppeennddeenntt eevvoolluuttiioonnaarryy oorriiggiinn ooff ssttrruuccttuurreess tthhaatt hhaavvee ssiimmiillaarr ffoorrmm oorr ffuunnccttiioonn HHoommoolologgyy • characters share similar design and common evolutionary origin – bird wing and mammal limb – sexual homologies - mammalian external genitalia

Figure 22.14 Homologous structures: anatomical signs of descent with modification AAnnaalologgyy

• Independent evolutionary origin of structures that have similar form or function – wings of birds and bees

– convergent evolution Figure 22.15 Different geographic regions, different mammalian “brands” FFigiguurere 1 133.8.8 A A c coommppaarrisisoonn o off m miMMittoossiiss aanititndd mmeeiooioossiissssisis aanndd MMeeioiossisis

• Mitosis – 2 daughter cells/division – Equal chromosomal separation - diploid daughter cells – Daughter cells identical to parent cell FFiigguurree 1 133..88MitosisMitosis AA ccoommppaarriissoonn ooff mmiittoossiiss a ndandand meiosis MeiosisMeiosis

• Meiosis – Male 4 cells/division – Female 1 cell/division • 2 polar bodies – Unequal division - haploid daughter cells – Daughter cells can be different from parent cell MMeeiioossiiss ggeenneerraatteess vvaarriiaabbiililittyy alternativeFigure 13 .9arrangements The results of alternative arrangemen tsof of two hhomologousomologous chromosome pairs o nchromosome the metaphase plate in pairs meiosis I MMeeiioossiiss ggeenneerraatteess vvaarriiaabbiililittyy

Figure 13.10 The resuAlts osf c roassi ngr oveer sduruingl mtei osois f crossing over AsexualAsexual ReproductionReproduction Figure 13.1 The asexual reproduction of a hydra

• all genes from one parent parent • fission - a separation of a parent into two or more individuals of about equal bud size (mitosis) • budding - new individuals split off parent Sexual Reproduction Sexual ReproductionFigure 13.4 The human life cycle

• genes from two parent • fusion of haploid gametes = diploid zygote • male gamete = sperm – usually smaller than oocyte • female gamete = ovum – egg/oocyte – usually larger than sperm • gamete also called germ cell ExternalExternal FertilizationFertilization • requires shedding of eggs and sperm • usually in moist environment – prevent egg desiccation – allow sperm transport • environmental factors can initiate release – temperature, rainfall, salinity, lunar cycle, pheromones, behavior InternalInternal FertilizationFertilization •• ccooooppeerraattiivvee mmaattiinngg •• bbeehhaavviioorr iimmppoorrttaanntt –– ccoouurrttsshhiipp –– mmaattee cchhooiiccee SexSex RatioRatio • Primary - male:female at fertilization – only those with genetic basis for sex determination • Secondary - at end of parental/incubation period • Tertiary - male: female adults in population